Address most of review comments

Author: Duhemm

compiler/src/dotty/tools/dotc/core/Symbols.scala

@@ -531,18 +531,6 @@ object Symbols {
     /** The current name of this symbol */
     final def name(implicit ctx: Context): ThisName = denot.name.asInstanceOf[ThisName]
 
-    def isHigherOrderTypeParameter(implicit ctx: Context): Boolean = this.maybeOwner.isTypeParameterOrSkolem
-    def isTypeParameterOrSkolem(implicit ctx: Context): Boolean = this.isTypeParam
-    def enclClassChain(implicit ctx: Context): List[Symbol] = this.maybeOwner.enclClassChain
-    final def isDerivedValueClass(implicit ctx: Context): Boolean =
-      isClass && !denot.is(Flags.Package) && !denot.is(Flags.Trait) &&
-        !ctx.phase.erasedTypes && denot.info.firstParent.typeSymbol == defn.AnyValClass && !denot.isPrimitiveValueClass
-
-    /** If this is a derived value class, return its unbox method
-     *  or NoSymbol if it does not exist.
-     */
-    def derivedValueClassUnbox(implicit ctx: Context): Symbol = NoSymbol
-
     /** The source or class file from which this class or
      *  the class containing this symbol was generated, null if not applicable.
      *  Overridden in ClassSymbol
@@ -649,30 +637,17 @@ object Symbols {
       denot.asInstanceOf[ClassDenotation]
 
     override protected def prefixString = "ClassSymbol"
-
-    override def enclClassChain(implicit ctx: Context): List[Symbol] =
-      if (this.is(Flags.PackageClass)) Nil
-      else this :: denot.owner.enclClassChain
-
-    override def derivedValueClassUnbox(implicit ctx: Context): Symbol =
-    // (info.decl(nme.unbox)) orElse      uncomment once we accept unbox methods
-      (denot.info.decls.find(_.denot.is(Flags.ParamAccessor | Flags.Method)))
-
   }
 
   class ErrorSymbol(val underlying: Symbol, msg: => String)(implicit ctx: Context) extends Symbol(NoCoord, ctx.nextId) {
     type ThisName = underlying.ThisName
     denot = underlying.denot
-
-    override def enclClassChain(implicit ctx: Context): List[Symbol] = Nil
   }
 
   @sharable object NoSymbol extends Symbol(NoCoord, 0) {
     denot = NoDenotation
     override def associatedFile(implicit ctx: Context): AbstractFile = NoSource.file
     override def recomputeDenot(lastd: SymDenotation)(implicit ctx: Context): SymDenotation = NoDenotation
-
-    override def enclClassChain(implicit ctx: Context): List[Symbol] = Nil
   }
 
   implicit class Copier[N <: Name](sym: Symbol { type ThisName = N })(implicit ctx: Context) {

compiler/src/dotty/tools/dotc/transform/Erasure.scala

@@ -750,7 +750,7 @@ object Erasure {
     case GenericArray(level, core) if !(core <:< defn.AnyRefType) =>
       level
     case AndType(tp1, tp2) =>
-      Math.max(unboundedGenericArrayLevel(tp1), unboundedGenericArrayLevel(tp2))
+      unboundedGenericArrayLevel(tp1) max unboundedGenericArrayLevel(tp2)
     case _ =>
       0
   }
@@ -760,15 +760,15 @@ object Erasure {
   // * type parameters appearing in method parameters
   // * type members not visible in an enclosing template
   private def isTypeParameterInSig(sym: Symbol, initialSymbol: Symbol)(implicit ctx: Context) = {
-    !sym.isHigherOrderTypeParameter &&
-      sym.isTypeParameterOrSkolem && (
-      (initialSymbol.enclClassChain.exists(sym isContainedIn _)) ||
+    !sym.maybeOwner.isTypeParam &&
+      sym.isTypeParam && (
+      sym.isContainedIn(initialSymbol.topLevelClass) ||
         (initialSymbol.is(Flags.Method) && initialSymbol.typeParams.contains(sym))
       )
   }
 
   final def javaSig(sym0: Symbol, info: Type)(implicit ctx: Context): Option[String] =
-    ctx.atPhase(ctx.erasurePhase) { implicit ctx => javaSig0(sym0, info) }
+    javaSig0(sym0, info)(ctx.withPhase(ctx.erasurePhase))
 
   @noinline
   private final def javaSig0(sym0: Symbol, info: Type)(implicit ctx: Context): Option[String] = {
@@ -944,9 +944,9 @@ object Erasure {
             else if (sym == defn.UnitClass) jsig(defn.BoxedUnitType)
             else builder.append(sym.info.toTag)
           }
-          else if (sym.isDerivedValueClass) {
-            val unboxed     = sym.derivedValueClassUnbox.info.finalResultType
-            val unboxedSeen = (tp.memberInfo(sym.derivedValueClassUnbox)).finalResultType
+          else if (ValueClasses.isDerivedValueClass(sym)) {
+            val unboxed     = ValueClasses.valueClassUnbox(sym.asClass).info.finalResultType
+            val unboxedSeen = tp.memberInfo(ValueClasses.valueClassUnbox(sym.asClass)).finalResultType
             if (unboxedSeen.isPrimitiveValueType && !primitiveOK)
               classSig
             else